1. Technical Field
The present invention relates to wireless communication and, more particularly, to a method and apparatus for performing cooperative transmission in a multi-node system.
2. Related Art
In a current wireless communication environment, the required amount of data for a communication network is rapidly increasing according to Machine-to-Machine (M2M) communication and the appearance and spread of various devices, such as smart phones and tablet PCs which require a great amount of data transmission. In order to satisfy a great amount of data transmission, communication technology is being developed into carrier aggregation technology for efficiently using a greater frequency band, cognitive radio technology, multi-antenna technology for increasing the data capacity within a limited frequency, multi-base station cooperation technology, and so on.
Furthermore, a wireless communication environment is evolving into an increase in the density of nodes which may access user peripheries. Here, the nodes refer to antennas or a group of antennas which are spaced apart from one another at specific intervals in a Distributed Antenna System (DAS). In the present invention, however, the nodes are not limited to the above meaning, but may be used in a broad sense. The node may include not only a macro base station in a cellular network, but also a device having a small coverage, such as a pico cell base station (PeNB), a home base station (HeNB), a Remote Radio Head (RRH), a Remote Radio Unit (RRU), a relay station, a distributed antenna, a WiFi Access Point (AP), a femto AP, or a pico AP.
A wireless communication system including a high density of nodes may have better system performance through cooperation between the nodes. That is, nodes cooperating with each other have more excellent system performance than nodes not cooperating with each other, each of which is operated as an independent Base Station (BS), Advanced BS (ABS), Node-B (NB), eNode-B (eNB), and AP.
There is a need for a method and apparatus which can perform cooperative transmission by utilizing each node in a multi-node system.